Nitro-2.3-dichlor-1.4-naphthoquinone and process of preparing the same



Patented Aug 21, 1928;

PATENT OFF/ICE.

JOSE]? szrocx,

s'rorr conroaarron, on NEW YORK,

nIrRo-as n1cnLon-1.i-narn'rnoaunvonn AND rnocnss or PREPARING THE sum F HOCHST-ON-THEMAIN, GERMANY, ASSIGNOR TO GRASSELLT DYE- N; Y., A CORPORATION OF DELAWARE;

No Drawing. Application filed November 30, 1927, Serial No. 236,874, and in Germany March 27, 1925.

My present invention relates to a nitro-Q 2.3-dichlor-1.4-naphthoquinone and process of preparing the same.

1.4-naphthoquinone and also 2.3-dichlor- 5 -1.4-naphthoquinone when treated with nitric acid are not transformed. as it could have been expected, into nitro-derivatives, but by the oxidizing action of the nitric acidinto phthalic acid (see Richter, Organische Chemie 1913, vol. 2, page 143, and; Graebe,

Liebigs Annalen, vol. 149, page 5). I have now found that nitro-derivatives of the 2.3-dichlor-1.4-naphthoquinone are obtained by causing nitri-sulfuric acid to act upon 2.3-dichlornaphthoquinone at an elevated temperature which may vary between the ordinary temperature and about 60 0.. preferably one between C.- and 60 C.

v This fact is all the "more surprising as in, 2 the 1.4-napthoquinohe the benzene ring linked to the quinone nucleus has a great resisting power to the introduction of acid substituents. Thus, if 1.4-1iaphthoquinone is thoroughly chlorinated in boiling glacial 'acetic acid by means of an excess of chlorine and iodine as carrier, the reaction ceases after the introducion of two chlorine atoms -the lat- .terenter the quinone nucleus with formation of 2.3-dichlog-lA-naphthoquinone (Berichte v der Deutschen Chemischen Gesellschaft vol.

34, page 1554) while the benzene nucleus remains unsubstituted.

- The following examples serve to illustrate my invention, but they are not intended to limit it thereto; the parts being by weight (1) One part of- 2,3-dichlor-L4-naphtho- (iuinone is heated with about 10 parts of nitricof nitric acid sulfuric acid ,containing 30% C for a short time to about 40 C, to

. 9 Even on gradually cooling, part of the nitroproduct wichhas been formedseparates as light-yello needles. ,In order to separate this produ t completely the reactiomrmxture is poured into'ice-water. filtered by suction, washed and dried. The crude product forms a light-yellow crystalline powder intermixed with coarse needle and themelting point of-which lies about C. to C. Its yield amounts to 9095% 1 of the theory.- The nitro dichlornaphthoquinone isobtainedin a pure state by recrystallizing the crude product from glacial acetic acid oralcohol. ;The,substance' crystal:

The precipitate is a lizes out of the said two solvents in two different crystalline forms, either as light-yel low need es or as yellow laminae. These two forms are chemically equivalent; they have stitutes most probably a 2.3-dichlor-8-nitro- 1.4-naphthoquinone which can be utilized particularly as intermediate product for the manufacture of vat-dyestuffs.

(2) If the nitric-sulfuric acid containing 30% of nitric acid, as used in Example 1, is

replaced by an acid containing a higher percentage, for instance 90%, of nitric acid and if otherwise the procedure of Example 1 is followed, a crude product having a melting point of about 140 C. to C. is obtained. By recrystallizing the letter from alcohol or glacial acetic acid, apure product is obtained possessing the properties of that obtainable according to Example 1.

I claim:

1. The process-of preparing a nitro-2.3-di v chlor-1.4-naphthoquinone "of the following formula:

which consists in causing nitric-sulfuric acid to act upon 2.3-ch1or-1.4-naphthoquinone at a temperature 'which may be varied between the ordinary temperature'and 60 C.

2. The process of preparing a-nitro-2.3-diehlor-lA-naphthoqumone of formula: F p

the following Q which consistsin causing nitric-sulfuric acid to act upon 2:3-chlor-1.4-naphthoquinone at a temperature which may be varied between 30 C. and 60 C. a

w 3. The process of preparing a nitroQB-di chlor-1.4-naphthoquinone of the following formula:

which consists in causing nitric-sulfuric acid ,to act upon 2.3-chlorl.4-naphthoquinone at a temperature between 40 C, and C. 4. The process of preparing a nitro-2.3-dichlor-1.4-naphthoquinone of the following formula formula which consistsin causing nitric-sulfuric acid containing 30% of nitric acid to act upon 2.3-chlor-lA-naphthoquinone at a temperature which may be varied between 30 C. and 60 C. for a short time.

6. The chlor-1.4-naphthoquinone of the following formula:

NO I

which consists in causing nitric-sulfuric acid containing 30% of nitric acid to act upon 2.3- chlor-lAc-naphthoquinone at a temperature between 40 C. and 50 C. for a short time.

7. As a new product, the compound of the following formula which when recrystallized from glacial acetic acid or alcohol forms crystals melting at 175 C.

In testimony whereof, I afiix my signature.

JOSEF STOCK process of preparing a nitro-2.3-di- 

